Elimination of Aluminum During the Process of Ti-6Al-4V Alloy, Smelting in a Vacuum Induction Furnace / Eliminacja Aluminium W Procesie Wytopu Stopu Ti-6Al-4V W Indukcyjnym Piecu Próżniowym

2012 ◽  
Vol 57 (4) ◽  
pp. 951-956 ◽  
Author(s):  
G. Siwiec
Keyword(s):  
Mass Transfer ◽  
Liquid Alloy ◽  
Pressure Range ◽  
Induction Furnace ◽  
Aluminum Concentration ◽  
Vacuum Induction Furnace ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Kinetics Of

In the paper, results of the study on kinetics of aluminum evaporation from a liquid Ti-6Al-4V alloy during its smelting in a vacuum induction furnace are presented. The experiments were performed with the use of a VIM 20-50 furnace (manufactured by SECO-WARWICK) at 1973 K and 5-1000 Pa. Based on the values of changes in aluminum concentration in a liquid alloy, overall mass transfer coefficients were estimated. Within the analysed pressure range, the coefficient values changed from 0.97·10-5 ms-1 to 1.93·10-5 ms-1 for 1000 Pa and 5 Pa, respectively

scholarly journals Extraction of Clove and Vetiver Oils with Supercritical Carbon Dioxide: Modeling and Simulation

2007 ◽  
Vol 1 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Julian Martínez ◽  
Paulo T.V. Rosa ◽  
M. Angela A. Meireles
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Large Scale ◽  
Raw Material ◽  
Feed Ratio ◽  
Transfer Model ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Extraction Curve ◽  
Kinetics Of

The kinetics of supercritical fluid extraction (SFE) of clove and vetiver oils using carbon dioxide as solvent was studied, in order to establish an efficient method to predict extraction curves on large scale. The mass transfer model of Sovová was used to adjust the experimental SFE data, which were obtained at 100 bar and 35 °C for clove and 200 bar and 40 °C for vetiver, using extraction columns of different geometry and solvent flow rates. Some other process parameters, such as bed density and porosity, solvent to feed ratio and solvent velocity were kept constant from one experiment to another, in order to verify if the mass transfer coefficients adjusted by the model varied. The results show that the model of Sovová was able to predict an overall extraction curve for clove from data obtained with twenty times less raw material, since the mass transfer coefficients remained the same and the predicted curves were similar to the observed ones. For vetiver, the simulation was not as effective, probably due to the effects of transport properties on the process.

Aluminium Evaporation from Titanium Alloys in the VIM Process

2013 ◽  
Vol 211 ◽  
pp. 117-128 ◽  
Author(s):  
Beata Oleksiak ◽  
Leszek Blacha ◽  
Lubomir Pikna ◽  
Rafał Burdzik
Keyword(s):  
Mass Transfer ◽  
Titanium Alloy ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Evaporation Rate ◽  
Induction Furnace ◽  
Vacuum Induction Furnace ◽  
Al Alloy ◽  
Overall Mass Transfer Coefficient ◽  
Kinetics Of

In the paper, results of the study on aluminium evaporation from the Ti-Al alloy (6.5%mass) during smelting in a vacuum induction furnace (VIM) are presented as well as the kinetics of the process is discussed. The experiments were performed at 51000 Pa for 1972 K and 2023 K. Based on the determined values of aluminium overall mass transfer coefficient, the mass transfer coefficient in the liquid phase and the evaporation rate constant, the stages that determined the investigated process were defined. It was demonstrated that Al evaporation from the aluminium-titanium alloy is kinetically controlled.

Henry's constants and mass transfer coefficients of halogenated organic pollutants in an air stripping packed column

1998 ◽  
Vol 38 (6) ◽  
pp. 287-294 ◽  
Author(s):  
Pen-C. Chiang ◽  
Chung-H. Hung ◽  
J. C. Mar ◽  
E. E. Chang
Keyword(s):  
Mass Transfer ◽  
Methylene Chloride ◽  
Packed Column ◽  
Transfer Coefficients ◽  
Chlorinated Organic Compounds ◽  
Air Stripping ◽  
Mass Transfer Coefficients ◽  
Equilibrium Partition ◽  
Henry's Constants ◽  
Chlorinated Organic

Both Henry's constants and volumetric mass transfer coefficients (KLa) of eight priority chlorinated organic compounds including 1,1-dichloroethene, methylene chloride, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,4-dichlorobenzene in an air stripping packed column were investigated in this study. The liquid and gas phase EPICS (Equilibrium Partition in Closed System) and direct calculating methods were applied to determine the Henry's constants of VOCs. The interference of co-solute on Henry's constants was also investigated. Experimental results indicated that decrease in Henry's constants of VOCs was observed in the presence of humic acid but no apparent effect on Henry's constants was detected when there was NaCl and surfactant in solution. Four different configurations of packing media including Intalox Saddle, Super Intalox Saddle, Telleret, and Hedgehog made of polypropylene were respectively packed in the air stripping tower and investigated in the study. The dependence of hydraulic loading, air-water ratio, and configurations of packing media on mass transfer coefficients of VOCs was discussed.

Transport of chlorinated hydrocarbons between sewage and sewer atmosphere

1996 ◽  
Vol 34 (3-4) ◽  
pp. 557-564 ◽  
Author(s):  
Bettina S. Haas ◽  
Reimer Herrmann
Keyword(s):  
Mass Transfer ◽  
Aromatic Compounds ◽  
Chlorinated Hydrocarbons ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Sewerage System ◽  
Mass Fluxes ◽  
Single Compound

Sewage containing volatile contaminants is a potential VOC-source in cities. Thus we tried to evaluate volatilization out of the sewerage system by measurements of contaminants in sewer gas and sewage. Our results from a medium sized town with little industry showed that sewer gas is mainly contaminated with alkanes, small aromatic compounds and chlorinated hydrocarbons. For three chlorinated hydrocarbons (chloroform, trichloroethene, tetrachloroethene) we determined mass transfer coefficients out of sewage and used these data to estimate mass fluxes from sewage and emissions out of the sewerage system for two sewer stretches. Considerable emission of chlorinated hydrocarbons from sewage, i.e. fluxes of some 10 to 100 g per m2·d, occurred only when the contaminant input via sewage was between some g and mg per litre for a single compound. For concentrations that were about 3 orders of magnitude less, emissions were negligible.

Mass Transfer in Liquid in an Apparatus with Mobile Packing. Application of a Dispersion Model

1993 ◽  
Vol 58 (5) ◽  
pp. 1078-1086
Author(s):  
Zdeněk Palatý
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Empirical Equation ◽  
Dispersion Model ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients

The paper deals with the mass transfer in a liquid on a plate with mobile packing. A procedure has been suggested which enables estimation of the mass transfer coefficients from experimental data considering the dispersion flow of the liquid. The results obtained from the desorption of CO2 from water are presented graphically and in the form of empirical equation.

On the convective diffusion under partial slip at wall

1989 ◽  
Vol 54 (4) ◽  
pp. 967-980 ◽  
Author(s):  
Ondřej Wein ◽  
Petr Kučera
Keyword(s):  
Mass Transfer ◽  
Numerical Solution ◽  
Analytic Solution ◽  
Convective Diffusion ◽  
Linear Velocity ◽  
Partial Slip ◽  
Accurate Calculation ◽  
Transfer Coefficients ◽  
Empirical Formulas ◽  
Mass Transfer Coefficients

Extended Leveque problem is studied for linear velocity profiles, vx(z) = u + qz. The existing analytic solution is reconsidered and shown to be inapplicable for the accurate calculation of mean mass-transfer coefficients. A numerical solution is reported and its accuracy is checked in detail. Simple but fairly accurate empirical formulas are suggested for the calculating of local and mean mass-transfer coefficients.

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